Nope. Merchants in 99% of the cases accept Bitcoin through a third party payment processor doing all the Bitcoin transaction processing for them. It basically means that merchants are exempt from the volatility. If merchants state that they quit because of the volatility, they are lying. It's either the lack of usage, or a policy change from higher authority. In most cases it's the first mentioned option due to the fees that people need to pay, where on top of that Bitcoin is a valuable asset with a lot forward growth capabilities -- selling or spending Bitcoin for that reason more often than not results in a big disappointment.